David Davis, Tory spokesman for the Grassroots Out campaign, said: ‘We are being held to ransom by the Turkish government. This whole charade proves what pitiful influence we have within the EU.

‘The fact we are set to give Turkey £500million to help them deal with their own crisis – and then allow 77million Turks visa-free access to Schengen by the summer as a bonus – demonstrates that the EU is a very weak negotiator in these matters, and is a club we are better off not being a part of.’

Human rights groups have also been scathing about a Europe preaching democracy but cutting a deal with a Turkish government accused of persecuting opponents and breaching human rights.

Many are concerned about a quickfire process of deporting everyone back to Turkey with little regard for individuals.

The summit comes after Turkish police raided the offices of Zaman, a top-selling newspaper critical of Turkey’s government, on Friday.

John O’Brennan, Jean Monnet Professor of European Integration at Maynooth University in Ireland, tweeted: ‘EU norms of pluralism are being completely eviscerated. By the European Union itself. Shame on this dirty deal with Turkey.’